Molded composition and method of making the same



Patenteil Feb. 22, 19.2 7.

UNITED STATES PATENT OFFICE.

NELSON 3. EMS, OF,DAY'1QN, OHIO, ASSIGNOB TO THE DAYTON ENGINEERING LABORATORIES COMPANY, 01' DAYTONIOEIO, A CORPORATION OF OHIO.

Eommn COMPOSITION Am mn'rnon or uaxmo THE sum.

No Drawing.

This invention relates to the manufacture of articles by molding dry mixtures of certain ingredients under heat and pressure, and particularly to the manufacture of. arti- 5 cles suitable for electrical insulation, bearings, and the like.

One object of my invention is to produce such articles at relatively low cost by molding ingredients which are relatively inexpensive. The object is accomplished by mixing with finel y divided woody material, such as powdered wood pulp, and a substance which is capable of being thoroughly mixed with the wood powder in a dry state and of functioning as a binder when the mixture is molded in a dry state under heat and pressure. I have discovered that dry, powdered silicic-acid makes a good binder in a dry molding process.

I am aware of the use of other compounds I "t of s111con, such as SOdlllIIl sllicate, as,

lnders for wood powder, but inmolding processes using sodiumsilicate, the mixture is molded I in a wet orplastic state. In the manufacture of electrical insulating arts, bearings and the like, the molding 0 dry mixtures can be "carried on with greater rapidity ease @and uniformity than the molding of -a wet or plastic mixture. Therefore the present invention possesses the advantages of ry molding known to molders of mixtures of wood powder and henolic condensation products and the ad 'tional advantage of relatlvely low cost due to the use of acheap binder.

. The silicic acid is formed by a combination ofcommercial hydrochloric acid and sodium s l cate. The result of this combination is silicic acid, a jelly-like substance which absorbs all water of crystallization, and exists'in the presence of sodium chloride. The chemical reaction is ,Ho1+N a. sio -.Naoi+H.sio.. I The reaction product is dried, pu lverized Y Application filed Apri1 14, 1925. Serial No. 28,148.

and mixed with wood pulp powder. For insulatingmaterialsnot under heavy mechanical stresses a dry mixture of.10% 'wood pulp'dpowder and 90% silicic acid has been foun satisfactory. The temperature employed in the molding press is about 300 F. and the pressure 8000 lbs. per square inch. For the .purpose of making bearing materials the proportions are approximately 25% wood pulp powder and 75% silicic' present" invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. 7

What is claimed is as follows: I

1. A material including a dry mixture of finely divided wood and silicic acid m'olded under heat and pressure.

29Material for insulating I purposes in-f eluding a mixture of approximately 10% of.

drywoodpulp powder and 90% of dry silicic acid moldedunder heat and pressure.

3. The method of making a molded material which comprises mixing in a dry state finely divided wood and silicic acid and molding under heat and pressure.

4. A molding substance including mixiture of finely divided wood an ac1 signature.

- NELSON. R. HAAS:

silicic In testimony whereof I hereto afiix my- 

